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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19607 results found.

  1. GRB 230420A: LCOGT Optical Upper Limit
  2. GRB 230420A: Enhanced Swift-XRT position
  3. IPN triangulation of GRB 230418A (short)
  4. GRB 230420A: Swift detection of a burst
  5. GRB 230418A: AstroSat CZTI detection
  6. GRB 230418A: Swift/BAT-GUANO detection outside the coded FOV
  7. GRB 230414B Swift-BAT refined analysis
  8. GRB 230415A: Fermi GBM detection
  9. GRB 230414B: Swift/UVOT Detection
  10. GRB 230414B: Osservatorio Astronomico Nastro Verde - Sorrento: optical observations
  11. GRB 230415A: Swift/BAT-GUANO detection
  12. GRB 230307A: iTelescope optical upper limit (likely)
  13. GRB 230414B: Montarrenti Observatory late time optical afterglow detection
  14. GRB 230414B: Lulin 40cm-SLT optical limit
  15. GRB 230414B: Bassano Bresciano Observatory optical observations
  16. GRB 230414B: AbAO optical observations
  17. GRB 230409B: 3.6m DOT near-infrared detection, afterglow confirmation
  18. GRB 230414B: Swift-XRT refined Analysis
  19. GRB 230414B: Dabancheng/GHOST optical observations
  20. GRB 230414B: SAO RAS optical observations
  21. GRB 230414B: Enhanced Swift-XRT position
  22. GRB 230414B: 1.3m DFOT Optical observations
  23. GRB 230414B: GROWTH India Telescope afterglow confirmation
  24. GRB 230414B: Nanshan/HMT optical afterglow detection
  25. GRB 230414A: Mondy optical afterglow candidate
  26. Swift GRB 230414B: Global MASTER-Net observations report
  27. GRB 230414B: Prompt enhanced Swift-XRT position
  28. GRB 230414B: Swift detection of a burst
  29. GRB 230328B: redshift lower limit estimating
  30. GRB 230409B: Mondy optical upper limit
  31. GRB 230409B: Swift-XRT refined Analysis
  32. GRB 230409B: Swift-BAT refined analysis
  33. Swift GRB 230409B: Global MASTER-Net observations report
  34. GRB 230409B: Swift/UVOT Detection
  35. GRB 230409B: Enhanced Swift-XRT position
  36. GRB 230409B: Swift detection of a burst
  37. GRB 230405B: VZLUSAT-2 detection
  38. Konus-Wind detection of GRB 230405B
  39. GRB 230405B: AGILE detection
  40. GRB 230405B: Swift-XRT refined Analysis
  41. GRB 230405B: Fermi GBM Observation
  42. GRB 230405B: MeerLICHT upper limits
  43. GRB 230405B: Swift/UVOT Upper Limits
  44. GRB 230405B: AstroSat CZTI detection
  45. GRB 230405B: Enhanced Swift-XRT position
  46. Swift GRB 230405B: Global MASTER-Net observations report
  47. GRB 230405B: Prompt enhanced Swift-XRT position
  48. GRB 230405B: Swift detection of a burst
  49. GRB 230307A: Chandra late-time detection of the X-ray afterglow
  50. GRB 230228A: detection by GTC of the potential host galaxy
  51. GRB 230328B: Swift/UVOT Detection
  52. GRB 230328B : GRANDMA/Kilonova-Catcher optical detection
  53. GRB 230328B: CAHA 2.2m/CAFOS detection
  54. GRB 230328B: 3.6m DOT multiband optical observation
  55. Konus-Wind detection of GRB 230328B
  56. GRB 230328B: GRBAlpha detection
  57. GRB 230328B: Swift-BAT refined analysis
  58. GRB 230328B: Nanshan/NEXT 2nd optical observation
  59. GRB 230328B: Liverpool Telescope afterglow detection
  60. GRB 230328B: GIT optical follow-up
  61. GRB 230328B: OASDG optical observations
  62. GRB 230328B: Nanshan/NEXT optical upper limit
  63. GRB 230328B: Swift-XRT refined Analysis
  64. GRB 230328B: AstroSat CZTI detection
  65. GRB 230328B: Fermi GBM observation
  66. GRB 230328B: Mondy, AbAO and Kitab optical observations
  67. GRB 230328B: Enhanced Swift-XRT position
  68. GRB 230328B: Mondy optical afterglow confirmation
  69. GRB 230328B: Swift detection of a burst with an optical afterglow
  70. GRB 230325A: Swift-BAT refined analysis
  71. GRB 230325A: Swift/UVOT Upper Limits
  72. GRB 230325A: Swift-XRT refined Analysis
  73. GRB 230322B: Swift-BAT refined analysis
  74. GRB 230325A: Enhanced Swift-XRT position
  75. GRB 230325A: Prompt enhanced Swift-XRT position
  76. GRB 230325A: Swift detection of a burst
  77. GRB 230320B: Fermi GBM Observation
  78. GRB 230322B: Swift/UVOT Detection
  79. GRB 230322B: Swift-XRT refined Analysis
  80. GRB 230322B: Enhanced Swift-XRT position
  81. Swift GRB 230322B: Global MASTER-Net observations report
  82. GRB 230322B: Swift detection of a burst with optical counterpart
  83. GRB 230320B: GRBAlpha detection
  84. GRB 230320B: Swift/BAT-GUANO detection outside the coded FOV
  85. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  86. IPN triangulation of GRB 230309A
  87. VZLUSAT-2 detection of SGR 1806-20
  88. GRB 230307A: Swift/UVOT detection
  89. GRB 230307A: soft X-ray detection with LEIA
  90. GRB 230307A: Swift-XRT afterglow detection
  91. Swift GRB230311.85: Global MASTER-Net observations report
  92. Swift GRB230311.83: Global MASTER-Net observations report
  93. Further improved IPN localization for GRB 230307A
  94. Swift GRB230311.81: Global MASTER-Net observations report
  95. GRB 230307A: SOAR/Goodman detection of the possible host galaxy
  96. Swift GRB230311.84: Global MASTER-Net observations report
  97. Swift Trigger 1159438 is also due to the Star Tracker loss of lock.
  98. Swift GRB230311.82: Global MASTER-Net observations report
  99. Triggers 1159434, 1159435 and 1159437: Swift detection of Sco X-1 due to Star Tracker loss of lock
  100. Trigger 1159327: Swift detection of SGR1806-20

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